During this work, all the planned aims and research objectives were successfully accomplished. However, there were a number of limitations and possibilities for future work in the proposed design. In addition, there is the possibility to enhance the performance of the developed end effectors. Some of these limitations, and a suggestion for future work, are illustrated below, and can perhaps solve the current design limitations.
i. Increase the reliability of the pneumatic muscle actuators by using more reliable materials in the construction of these actuators. This may include trying another
171 construction scheme instead of the McKibben muscle configuration. During the development of this work, only a single puncture occurred in one of the test muscles, however, in order to be of practical use, the material used to implement the soft robot needs to be more reliable.
ii. The PID controller is widely accepted as not being the best technique to control soft robots, which are likely to be highly nonlinear in their operational characteristics. Whilst the experimental results have shown that the fingers can be controlled, the accuracy is likely to be greatly improved if other control techniques are used, and this could well form a significant part of the future direction of the research.
iii. Using an adaptive control scheme to control the performance of the pneumatic continuum soft robot arm and its end effectors will increase the overall reliability of the system. An adaptive controller would reduce the effect of any external disturbances that might occur during the operation of the proposed soft robot end effectors. In addition, an adaptive controller would deal better with the nonlinearity of these soft robot systems.
iv. One of the adaptive control schemes that can be used in the proposed pneumatic variable stiffness soft robot arm and its end effectors is that of Neuro-Fuzzy techniques to tune the parameters of the PID controller. This will modify the performance of the PID controller to be able to deal with the nonlinearity of the systems.
v. A five-fingered soft robotics hand could be designed that can imitate the operation of the human hand. The suggested soft robotics hand could be constructed using the same soft, low cost and safe materials investigated in the course of this research. This five-fingered soft hand may be used directly by disabled people, for instance.
172
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